Eukaryotic cells are compartmentalized into discrete organelles, which allow a spatial division of labor. An universal feature of eukaryotic cells is that the various lipid species, and in particular sterols, are unevenly distributed between organelles. The precise distribution of lipids is ensured by vesicular and non-vesicular transport pathways. Several protein families are involved in non-vesicular lipid transport. Intriguingly, some of these proteins are loca ! lized in specific regions of the cell, named membrane contact sites, where the membranes of two distinct organelles are in close proximity. It is increasingly clear that contact sites between organelles are zones of active non-vesicular lipid traffic. This idea will be illustrated by the data our team obtained on STARD3, a cholesterol-specific transporter, which scaffolds ER-endosome contacts and modulates cellular cholesterol repartition by delivering cholesterol to endosomes.